Shareholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 30, 2021	Feb. 01, 2020	Jan. 30, 2021	Feb. 01, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 0.0		$ 0.0
2014 Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2.4	$ 1.6	4.3	$ 5.6
2014 Incentive Plan | PSAs | Executives and non-executive members of management
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense		1.3		3.6
2014 Incentive Plan | RSUs | Executives and non-executive members of management
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$ 2.4	$ 0.3	3.4	1.1
2014 Incentive Plan | RSAs | Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 0.9	$ 0.9